On 2/25/15 4:55 PM, Xinok wrote:
On Wednesday, 25 February 2015 at 21:25:49 UTC, Daniel N wrote:
Just throwing an idea out there... How about using annotations to
teach the compiler which functions are inverses of each-other, in
order to facilitate optimizing away certain redundant operations even
if they are located inside a library(i.e. no source).
A little pseudo-code for illustrational purposes, in case my above
text is incomprehensible:
void inc() pure nothrow @inverse(dec)
void dec() pure nothrow @inverse(inc)
void swap(T)(ref T lhs, ref T rhs) pure nothrow @inverse(swap!T)
I like the idea but feel that it's application is too narrow. I prefer
features which are more general and offer greater flexibility. I believe
I've read somewhere that some [functional] languages define common
patterns and equivalent substitutions for optimization purposes.
inc(dec(x)) -> x
dec(inc(x)) -> x
cos(x)^^2 + sin(x)^^2 -> 1
Since you're here, do you plan to fix stable sort as recently discussed?
-- Andrei
